Lowering the emission of greenhouse gases into the atmosphere will call for a major effort, especially to reduce the amount of anthropogenic CO2 emissions. Approximately one-third of the CO2 released by humans into the atmosphere stems from the production of energy, a process during which mostly fossil fuels are burned in power plants in order to generate electricity. Particularly the use of modern technologies as well as additional political initiatives will translate into a considerable savings potential in the energy-producing sector in terms of avoiding a further increase in CO2 emissions.
A technically feasible way to reduce CO2 emissions in thermal power plants consists of extracting carbon from the fuels used for combustion processes. This requires an appropriate pretreatment of the fuel involving, for example, partial oxidation of the fuel with oxygen and/or a pretreatment of the fuel with steam. Such pretreated fuels usually have a high content of H2 and CO and, depending on the mixing ratios, exhibit heating values that, as rule, are below those of natural gas (NG). Consequently, such synthetically produced gases are referred to as MBtu gases or LBtu gases, depending on their heating value.
Due to their properties, such gases do not readily lend themselves for use in conventional burners designed for the combustion of natural gas of the type described, for example, in European patent specification EP 0 321 809 B1, European patent application EP 0 780 629 A2, international patent specification WO 93/17279 or European patent application EP 1 070 915 A1. In these burners, which work with a fuel premix, a conically widening vortex flow consisting of combustion air and admixed fuel is generated in the direction of flow, and this vortex flow becomes increasingly unstable in the direction of flow after exiting from the burner, preferably having been completely and homogenously mixed by means of the increasing swirling, and it then makes a transition to an annular vortex flow with backflow in the core.